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/ IRIX Base Documentation 2001 May / SGI IRIX Base Documentation 2001 May.iso / usr / share / catman / p_man / cat3dm / audio / ALqueryparams.z / ALqueryparams
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Text File  |  1998-10-20  |  8.3 KB  |  133 lines
  1.  
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  4. AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm))))                                          AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm))))
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  7.  
  8. NNNNAAAAMMMMEEEE
  9.      ALqueryparams - (obsolete) get descriptor/description pairs for audio
  10.      device state variables
  11.  
  12. SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
  13.      ####iiiinnnncccclllluuuuddddeeee <<<<ddddmmmmeeeeddddiiiiaaaa////aaaauuuuddddiiiioooo....hhhh>>>>
  14.  
  15.      lllloooonnnngggg AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((lllloooonnnngggg ddddeeeevvvviiiicccceeee,,,, lllloooonnnngggg ****PPPPVVVVbbbbuuuuffffffffeeeerrrr,,,, lllloooonnnngggg bbbbuuuuffffffffeeeerrrrlllleeeennnnggggtttthhhh))))
  16.  
  17. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR
  18.      _d_e_v_i_c_e         expects a device.  Currently, there is only one device,
  19.                     AL_DEFAULT_DEVICE.
  20.  
  21.      _P_V_b_u_f_f_e_r       expects an array of longs into which AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm))))
  22.                     can write descriptor/description pairs for each state
  23.                     variable associated with _d_e_v_i_c_e.  The even (0,2,4, ...)
  24.                     entries receive the descriptors. The odd entries (1,3,5,
  25.                     ...) receive the descriptions.  These descriptions take on
  26.                     one of four values:
  27.  
  28.                     ++++////----AAAALLLL____RRRRAAAANNNNGGGGEEEE____VVVVAAAALLLLUUUUEEEE if this device state variable can assume
  29.                     a range of values, and the range has some meaning, i.e.
  30.                     larger values mean more of whatever this parameter
  31.                     controls.  A value of ----AAAALLLL____RRRRAAAANNNNGGGGEEEE____VVVVAAAALLLLUUUUEEEE indicates that the
  32.                     parameter is read-only.
  33.  
  34.                     ++++////----AAAALLLL____EEEENNNNUUUUMMMM____VVVVAAAALLLLUUUUEEEE  if this device state variable assumes
  35.                     values from an enumerated type.  They still have a limited
  36.                     range, but there is no inherent relationship between them.
  37.                     A value of ----AAAALLLL____EEEENNNNUUUUMMMM____VVVVAAAALLLLUUUUEEEE indicates that the parameter is
  38.                     read-only.
  39.  
  40.      _b_u_f_f_e_r_l_e_n_g_t_h   expects the length of the buffer, in longs, pointed to by
  41.                     _P_V_b_u_f_f_e_r.
  42.  
  43. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  44.      AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss is obsolete and is provided for backward compatibility. The
  45.      preferred method is to use aaaallllQQQQuuuueeeerrrryyyyVVVVaaaalllluuuueeeessss((((3333ddddmmmm)))) with the AL_PARAMS
  46.      parameter to list the supported parameters, followed by
  47.      aaaallllGGGGeeeettttPPPPaaaarrrraaaammmmIIIInnnnffffoooo((((3333ddddmmmm)))) to get information about each supported parameter.
  48.  
  49.      AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm)))) lets you get a list of descriptors for all the state
  50.      variables associated with the specified device.
  51.  
  52.      AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm)))) also tells you whether the value of a state variable
  53.      must be one of a set of enumerated types or any number within a specific
  54.      range.  In both cases the values are numbers within the range returned by
  55.      AAAALLLLggggeeeettttmmmmiiiinnnnmmmmaaaaxxxx((((3333ddddmmmm)))) and have the default value returned by
  56.      AAAALLLLggggeeeettttddddeeeeffffaaaauuuulllltttt((((3333ddddmmmm)))).
  57.  
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  62.  
  63.                                                                         PPPPaaaaggggeeee 1111
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  70. AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm))))                                          AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm))))
  71.  
  72.  
  73.  
  74.      Typical device parameters are expected to be things like volume and
  75.      sample rate. You can find a list of parameters and their descriptions in
  76.      AAAALLLLggggeeeettttppppaaaarrrraaaammmmssss((((3333ddddmmmm)))).
  77.  
  78.      AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm)))) returns the length of the buffer (number of longs)
  79.      that is required to hold all pairs of descriptors/descriptions. If
  80.      _P_V_b_u_f_f_e_r is smaller than this value, you have not acquired a complete
  81.      list of descriptor/description pairs and should increase your _P_V_b_u_f_f_e_r
  82.      and try again.
  83.  
  84.      To simply determine the size of the buffer needed to hold the parameters
  85.      and descriptions, call AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm)))) with _b_u_f_f_e_r_l_e_n_g_t_h set to zero.
  86.  
  87.      AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm)))) can fail for the following reasons:
  88.  
  89.      AAAALLLL____BBBBAAAADDDD____DDDDEEEEVVVVIIIICCCCEEEE             _d_e_v_i_c_e is not valid.
  90.  
  91.      AAAALLLL____BBBBAAAADDDD____PPPPVVVVBBBBUUUUFFFFFFFFEEEERRRR           _P_V_b_u_f_f_e_r is null valued.
  92.  
  93.      AAAALLLL____BBBBAAAADDDD____BBBBUUUUFFFFFFFFEEEERRRRLLLLEEEENNNNGGGGTTTTHHHH____OOOODDDDDDDD   _b_u_f_f_e_r_l_e_n_g_t_h is odd.
  94.  
  95.      AAAALLLL____BBBBAAAADDDD____BBBBUUUUFFFFFFFFEEEERRRRLLLLEEEENNNNGGGGTTTTHHHH____NNNNEEEEGGGG   _b_u_f_f_e_r_l_e_n_g_t_h is negative.
  96.  
  97.      AAAALLLL____BBBBAAAADDDD____DDDDEEEEVVVVIIIICCCCEEEE____AAAACCCCCCCCEEEESSSSSSSS      audio hardware is inaccessible.
  98.  
  99. EEEEXXXXAAAAMMMMPPPPLLLLEEEE
  100.                #include <dmedia/audio.h>
  101.                #include <malloc.h>
  102.                ...
  103.                /* Get a buffer containing all the device parameters. */
  104.                long *buf,buflen;
  105.                buflen=ALqueryparams(AL_DEFAULT_DEVICE,0,0);
  106.                buf=(long *)malloc(buflen*sizeof(long));
  107.                (void)ALqueryparams(AL_DEFAULT_DEVICE,buf,buflen);
  108.  
  109.  
  110. DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
  111.      Upon successful completion AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm)))) returns the size of the
  112.      buffer, in longs, needed to hold all the descriptor/description pairs for
  113.      _d_e_v_i_c_e. Otherwise, AAAALLLLqqqquuuueeeerrrryyyyppppaaaarrrraaaammmmssss((((3333ddddmmmm)))) returns -1 and sets an error number
  114.      which can be retrieved with oooosssseeeerrrrrrrroooorrrr((((3333CCCC)))).
  115.  
  116. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  117.      ALgetparams(3dm), ALsetparams(3dm), ALgetminmax(3dm), ALgetname(3dm),
  118.      ALgetdefault(3dm), ALsetdevice(3dm), oserror(3C)
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  128.  
  129.                                                                         PPPPaaaaggggeeee 2222
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